Method and apparatus for positioning based on validity information and reporting the result in rrc_inactive in mobile wireless communication system

ABSTRACT

A method and apparatus for positioning in a mobile communication system are provided. Method for positioning includes receiving from a base station a first type1 assistance data, receiving from the base station a type2 assistance data, the type2 assistance data includes a validity information and a second type1 assistance data, determining based on the validity information and a New Radio (NR) cell global identifier of serving cell whether the second type1 assistance data is valid, receiving from the base station a RRCRelease, transmitting in RRC_INACTIVE state a ProvideLocationInformation. At least a part of the ProvideLocationInformation is transmitted in a first Medium Access Control (MAC) Protocol Data Unit (PDU) and the first MAC PDU includes a ResumeRequest.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a US Bypass Continuation application ofInternational Application No. PCT/KR2022/014217, filed on Sep. 23, 2022,which claims priority to and the benefit of Korean Patent ApplicationNo. 10-2021-00131349, filed on Oct. 5, 2021, the disclosure of which isincorporated herein by reference in its entirety.

BACKGROUND Technical Field

The present disclosure relates to positioning in a mobile communicationsystem. More specifically, the present disclosure relates to performingpositioning based on validity information and reporting the result inRRC_INACTIVE.

Related Art

To meet the increasing demand for wireless data traffic since thecommercialization of 4th generation (4G) communication systems, the 5thgeneration (5G) system is being developed. For the sake of high, 5Gsystem introduced millimeter wave (mmW) frequency bands (e. g. 60 GHzbands). In order to increase the propagation distance by mitigatingpropagation loss in the 5G communication system, various techniques areintroduced such as beamforming, massive multiple-input multiple output(MIMO), full dimensional MIMO (FD-MIMO), array antenna, analogbeamforming, and large-scale antenna. In addition, base station isdivided into a central unit and plurality of distribute units for betterscalability. To facilitate introduction of various services, 5Gcommunication system targets supporting higher data rate and smallerlatency.

Various attempts are being made to apply the 5G communication system tothe IoT network. For example, 5G communication such as sensor network,machine to machine communication (M2M), and machine type communication(MTC) is being implemented by techniques such as beam forming, MIMO, andarray antenna.

The importance of terminal positioning in new services such as theabove-mentioned machine communication is increasing. Positioning can beestimated in consideration of the measurement result of the base stationmeasuring the uplink reference signal transmitted by the terminal or themeasurement result of the terminal measuring the downlink referencesignal transmitted by the base station.

SUMMARY

Aspects of the present disclosure are to address positioning based onvalidity information in mobile communication system. Accordingly, anaspect of the present disclosure includes receiving from a base stationa first type1 assistance data, receiving from the base station a type2assistance data, the type2 assistance data includes a validityinformation and a second type1 assistance data, determining based on thevalidity information and a New Radio (NR) cell global identifier ofserving cell whether the second type1 assistance data is valid,receiving from the base station a RRCRelease, transmitting inRRC_INACTIVE state a ProvideLocationInformation. At least a part of theProvideLocationInformation is transmitted in a first Medium AccessControl (MAC) Protocol Data Unit (PDU) and the first MAC PDU includes aResumeRequest.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a diagram illustrating the architecture of an 5G system and aNG-RAN.

FIG. 1B is a diagram illustrating a wireless protocol architecture in an5G system.

FIG. 1C is a diagram illustrating the architecture of positioningsystem.

FIG. 1D is a diagram illustrating the protocol architecture ofpositioning system.

FIG. 2A is a diagram illustrating positioning method according to thefirst embodiment of the present invention.

FIG. 2B is a diagram illustrating the mapping between positioningassistance data and positioning system information block.

FIG. 2C is a diagram illustrating a structure of immediate downlinkpositioning reference signal assistance data according to the firstembodiment of the present invention.

FIG. 2D is a diagram illustrating a structure of conditional downlinkpositioning reference signal assistance data according to the firstembodiment of the present invention.

FIG. 2E is a diagram illustrating system information acquisitionprocedure according to the first embodiment of the present invention.

FIG. 2F is a diagram illustrating system information request procedureaccording to the first embodiment of the present invention.

FIG. 2G is a diagram illustrating structures of an uplink MAC PDUincluding positioning measurement result in RRC_INACTIVE.

FIG. 2H is a diagram illustrating structures of a first buffer statusreport MAC CE and a second buffer status MAC CE.

FIG. 3A is a flow diagram illustrating an operation of a terminal and abase station and an LMF.

FIG. 3B is a flow diagram illustrating terminal capability reportingprocedure.

FIG. 3C is a flow diagram illustrating assistance data deliveryprocedure.

FIG. 3D is a flow diagram illustrating uplink positioning procedure ofterminal in RRC_INACTIVE.

FIG. 3E is a flow diagram illustrating downlink positioning procedure ofterminal in RRC_INACTIVE.

FIG. 4 is a diagram illustrating operation of terminal according to thefirst embodiment of the present invention.

FIG. 5A is a block diagram illustrating the internal structure of a UEto which the disclosure is applied.

FIG. 5B is a block diagram illustrating the configuration of a basestation according to the disclosure.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of variousembodiments of the present disclosure as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the various embodiments describedherein can be made without departing from the scope and spirit of thepresent disclosure. In addition, descriptions of well-known functionsand constructions may be omitted for clarity and conciseness.

The terms used, in the following description, for indicating accessnodes, network entities, messages, interfaces between network entities,and diverse identity information is provided for convenience ofexplanation. Accordingly, the terms used in the following descriptionare not limited to specific meanings but may be replaced by other termsequivalent in technical meanings.

In the following descriptions, the terms and definitions given in the3GPP standards are used for convenience of explanation. However, thepresent disclosure is not limited by use of these terms and definitionsand other arbitrary terms and definitions may be employed instead.

Table 1 lists the acronyms used throughout the present disclosure.

TABLE 1 Acronym Full name Acronym Full name 5GC 5G Core Network RACHRandom Access Channel ACK Acknowledgement RAN Radio Access Network AMAcknowledged Mode RA-RNTI Random Access RNTI AMF Access and Mobility RATRadio Access Technology Management Function ARQ Automatic Repeat RequestRB Radio Bearer AS Access Stratum RLC Radio Link Control ASN.1 AbstractSyntax Notation One RNA RAN-based Notification Area BSR Buffer StatusReport RNAU RAN-based Notification Area Update BWP Bandwidth Part RNTIRadio Network Temporary Identifier CA Carrier Aggregation RRC RadioResource Control CAG Closed Access Group RRM Radio Resource ManagementCG Cell Group RSRP Reference Signal Received Power C-RNTI Cell RNTI RSRQReference Signal Received Quality CSI Channel State Information RSSIReceived Signal Strength Indicator DCI Downlink Control SCell SecondaryCell Information DRB (user) Data Radio Bearer SCS Subcarrier Spacing DRXDiscontinuous Reception SDAP Service Data Adaptation Protocol HARQHybrid Automatic Repeat SDU Service Data Unit Request IE Informationelement SFN System Frame Number LCG Logical Channel Group S-GW ServingGateway MAC Medium Access Control SI System Information MIB MasterInformation Block SIB System Information Block NAS Non-Access StratumSpCell Special Cell NG-RAN NG Radio Access Network SRB Signalling RadioBearer NR NR Radio Access SRS Sounding Reference Signal PBR PrioritisedBit Rate SSB SS/PBCH block PCell Primary Cell SSS SecondarySynchronisation Signal PCI Physical Cell Identifier SUL SupplementaryUplink PDCCH Physical Downlink Control TM Transparent Mode Channel PDCPPacket Data Convergence UCI Uplink Control Information Protocol PDSCHPhysical Downlink Shared UE User Equipment Channel PDU Protocol DataUnit UM Unacknowledged Mode PHR Power Headroom Report CRP CellReselection Priority PLMN Public Land Mobile Network LPP LTE positioningprotocol PRACH Physical Random Access posSIB positioning SIB Channel PRBPhysical Resource Block posSI positioning System Information PSS PrimarySynchronisation TRP Transmission-Reception Signal Point PUCCH PhysicalUplink Control DL- Downlink Time Difference Of Channel TDOA ArrivalPUSCH Physical Uplink Shared Channel

Table 2 lists the terminologies and their definition used throughout thepresent disclosure.

TABLE 2 Terminology Definition allowedCG-List List of configured grantsfor the corresponding logical channel. This restriction applies onlywhen the UL grant is a configured grant. If present, UL MAC SDUs fromthis logical channel can only be mapped to the indicated configuredgrant configuration. If the size of the sequence is zero, then UL MACSDUs from this logical channel cannot be mapped to any configured grantconfigurations. If the field is not present, UL MAC SDUs from thislogical channel can be mapped to any configured grant configurations.allowedSCS-List List of allowed sub-carrier spacings for thecorresponding logical channel. If present, UL MAC SDUs from this logicalchannel can only be mapped to the indicated numerology. Otherwise, ULMAC SDUs from this logical channel can be mapped to any configurednumerology. allowedServingCells List of allowed serving cells for thecorresponding logical channel. If present, UL MAC SDUs from this logicalchannel can only be mapped to the serving cells indicated in this list.Otherwise, UL MAC SDUs from this logical channel can be mapped to anyconfigured serving cell of this cell group. Carrier frequency centerfrequency of the cell. Cell combination of downlink and optionallyuplink resources. The linking between the carrier frequency of thedownlink resources and the carrier frequency of the uplink resources isindicated in the system information transmitted on the downlinkresources. Cell Group in dual connectivity, a group of serving cellsassociated with either the MeNB or the SeNB. Cell reselection A processto find a better suitable cell than the current serving cell based onthe system information received in the current serving cell Cellselection A process to find a suitable cell either blindly or based onthe stored information Dedicated signalling Signalling sent on DCCHlogical channel between the network and a single UE. discardTimer Timerto control the discard of a PDCP SDU. Starting when the SDU arrives.Upon expiry, the SDU is discarded. F The Format field in MAC subheaderindicates the size of the Length field. Field The individual contents ofan information element are referred to as fields. Frequency layer set ofcells with the same carrier frequency. Global cell identity An identityto uniquely identifying an NR cell. It is consisted of cellIdentity andplmn-Identity of the first PLMN-Identity in plmn- IdentityList in SIB1.gNB node providing NR user plane and control plane protocol terminationstowards the UE, and connected via the NG interface to the 5GC. Handoverprocedure that changes the serving cell of a UE in RRC_CONNECTED.Information element A structural element containing single or multiplefields is referred as information element. L The Length field in MACsubheader indicates the length of the corresponding MAC SDU or of thecorresponding MAC CE LCID 6 bit logical channel identity in MACsubheader to denote which logical channel traffic or which MAC CE isincluded in the MAC subPDU MAC-I Message Authentication Code -Integrity. 16 bit or 32 bit bit string calculated by NR IntegrityAlgorithm based on the security key and various fresh inputs Logicalchannel a logical path between a RLC entity and a MAC entity. There aremultiple logical channel types depending on what type of information istransferred e.g. CCCH (Common Control Channel), DCCH (Dedicate ControlChannel), DTCH (Dedicate Traffic Channel), PCCH (Paging Control Channel)LogicalChannelConfig The IE LogicalChannelConfig is used to configurethe logical channel parameters. It includes priority,prioritisedBitRate, allowedServingCells, allowedSCS-List,maxPUSCH-Duration, logicalChannelGroup, allowedCG-List etclogicalChannelGroup ID of the logical channel group, as specified in TS38.321, which the logical channel belongs to MAC CE Control Elementgenerated by a MAC entity. Multiple types of MAC CEs are defined, eachof which is indicated by corresponding LCID. A MAC CE and acorresponding MAC sub- header comprises MAC subPDU Master Cell Group inMR-DC, a group of serving cells associated with the Master Node,comprising of the SpCell (PCell) and optionally one or more SCells.maxPUSCH- Restriction on PUSCH-duration for the corresponding logicalDuration channel. If present, UL MAC SDUs from this logical channel canonly be transmitted using uplink grants that result in a PUSCH durationshorter than or equal to the duration indicated by this field.Otherwise, UL MAC SDUs from this logical channel can be transmittedusing an uplink grant resulting in any PUSCH duration. NR NR radioaccess PCell SpCell of a master cell group. PDCP entity The processtriggered upon upper layer request. It includes the reestablishmentinitialization of state variables, reset of header compression andmanipulating of stored PDCP SDUs and PDCP PDUs. The details can be foundin 5.1.2 of 38.323 PDCP suspend The process triggered upon upper layerrequest. When triggered, transmitting PDCP entity set TX_NEXT to theinitial value and discard all stored PDCP PDUs. The receiving entitystop and reset t-Reordering, deliver all stored PDCP SDUs to the upperlayer and set RX_NEXT and RX_DELIV to the initial value PDCP-config TheIE PDCP-Config is used to set the configurable PDCP parameters forsignalling and data radio bearers. For a data radio bearer,discardTimer, pdcp-SN-Size, header compression parameters, t-Reorderingand whether integrity protection is enabled are configured. For asignaling radio bearer, t-Reordering can be configured PLMN ID Check theprocess that checks whether a PLMN ID is the RPLMN identity or an EPLMNidentity of the UE. Primary Cell The MCG cell, operating on the primaryfrequency, in which the UE either performs the initial connectionestablishment procedure or initiates the connection re-establishmentprocedure. Primary SCG Cell For dual connectivity operation, the SCGcell in which the UE performs random access when performing theReconfiguration with Sync procedure. priority Logical channel priority,as specified in TS 38.321. an integer between 0 and 7. 0 means thehighest priority and 7 means the lowest priority PUCCH SCell a SecondaryCell configured with PUCCH. Radio Bearer Logical path between a PDCPentity and upper layer (i.e. SDAP entity or RRC) RLC bearer RLC and MAClogical channel configuration of a radio bearer in one cell group. RLCbearer The lower layer part of the radio bearer configuration comprisingconfiguration the RLC and logical channel configurations. RX_DELIV Thisstate variable indicates the COUNT value of the first PDCP SDU notdelivered to the upper layers, but still waited for. RX_NEXT This statevariable indicates the COUNT value of the next PDCP SDU expected to bereceived. RX_REORD This state variable indicates the COUNT valuefollowing the COUNT value associated with the PDCP Data PDU whichtriggered t-Reordering. Serving Cell For a UE in RRC_CONNECTED notconfigured with CA/DC there is only one serving cell comprising of theprimary cell. For a UE in RRC_CONNECTED configured with CA/DC the term‘serving cells’ is used to denote the set of cells comprising of theSpecial Cell(s) and all secondary cells. SpCell primary cell of a masteror secondary cell group. Special Cell For Dual Connectivity operationthe term Special Cell refers to the PCell of the MCG or the PSCell ofthe SCG, otherwise the term Special Cell refers to the PCell. SRBSignalling Radio Bearers” (SRBs) are defined as Radio Bearers (RBs) thatare used only for the transmission of RRC and NAS messages. SRB0 SRB0 isfor RRC messages using the CCCH logical channel SRB1 SRB1 is for RRCmessages (which may include a piggybacked NAS message) as well as forNAS messages prior to the establishment of SRB2, all using DCCH logicalchannel; SRB2 SRB2 is for NAS messages and for RRC messages whichinclude logged measurement information, all using DCCH logical channel.SRB2 has a lower priority than SRB1 and may be configured by the networkafter AS security activation; SRB3 SRB3 is for specific RRC messageswhen UE is in (NG)EN-DC or NR-DC, all using DCCH logical channel SRB4SRB4 is for RRC messages which include application layer measurementreporting information, all using DCCH logical channel. Suitable cell Acell on which a UE may camp. Following criteria apply The cell is partof either the selected PLMN or the registered PLMN or PLMN of theEquivalent PLMN list The cell is not barred The cell is part of at leastone TA that is not part of the list of “Forbidden Tracking Areas forRoaming” (TS 22.011 [18]), which belongs to a PLMN that fulfils thefirst bullet above. The cell selection criterion S is fulfilled (i.e.RSRP and RSRQ are better than specific values

In the present invention, “trigger” or “triggered” and “initiate” or“initiated” may be used in the same meaning.

In the present invention, “radio bearers allowed for the second resumeprocedure”, “radio bearers for which the second resume procedure isset”, and “radio bearers for which the second resume procedure isenabled” may all have the same meaning.

FIG. 1A is a diagram illustrating the architecture of an 5G system and aNG-RAN to which the disclosure may be applied.

5G system consists of NG-RAN 1A-01 and 5GC 1A-02. An NG-RAN node iseither:

-   -   a gNB, providing NR user plane and control plane protocol        terminations towards the UE; or    -   an ng-eNB, providing E-UTRA user plane and control plane        protocol terminations towards the UE.

The gNBs 1A-05 or 1A-06 and ng-eNBs 1A-03 or 1A-04 are interconnectedwith each other by means of the Xn interface. The gNBs and ng-eNBs arealso connected by means of the NG interfaces to the 5GC, morespecifically to the AMF Access and Mobility Management Function) and tothe UPF (User Plane Function). AMF 1A-07 and UPF 1A-08 may be realizedas a physical node or as separate physical nodes.

A gNB 1A-05 or 1A-06 or an ng-eNBs 1A-03 or 1A-04 hosts the functionslisted below.

-   -   Functions for Radio Resource Management such as Radio Bearer        Control, Radio Admission Control, Connection Mobility Control,        Dynamic allocation of resources to UEs in uplink, downlink and        sidelink (scheduling); and    -   IP and Ethernet header compression, uplink data decompression        and encryption of user data stream; and    -   Selection of an AMF at UE attachment when no routing to an MME        can be determined from the information provided by the UE; and    -   Routing of User Plane data towards UPF; and    -   Scheduling and transmission of paging messages; and    -   Scheduling and transmission of broadcast information (originated        from the AMF or O&M); and    -   Measurement and measurement reporting configuration for mobility        and scheduling; and    -   Session Management; and    -   QoS Flow management and mapping to data radio bearers; and    -   Support of UEs in RRC_INACTIVE state; and    -   Radio access network sharing; and    -   Tight interworking between NR and E-UTRA; and    -   Support of Network Slicing.

The AMF 1A-07 hosts the functions such as NAS signaling, NAS signalingsecurity, AS security control, SMF selection, Authentication, Mobilitymanagement and positioning management.

The UPF 1A-08 hosts the functions such as packet routing and forwarding,transport level packet marking in the uplink, QoS handling and thedownlink, mobility anchoring for mobility etc.

FIG. 1B is a diagram illustrating a wireless protocol architecture in an5G system to which the disclosure may be applied.

User plane protocol stack consists of SDAP 1B-01 or 1B-02, PDCP 1B-03 or1B-04, RLC 1B-05 or 1B-06, MAC 1B-07 or 1B-08 and PHY 1B-09 or 1B-10.Control plane protocol stack consists of NAS 1B-11 or 1B-15, RRC 1B-13or 1B-14, PDCP, RLC, MAC and PHY.

Each protocol sublayer performs functions related to the operationslisted in the table 3.

TABLE 3 Sub- layer Functions NAS authentication, mobility management,security control etc RRC System Information, Paging, Establishment,maintenance and release of an RRC connection, Security functions,Establishment, configuration, maintenance and release of SignallingRadio Bearers (SRBs) and Data Radio Bearers (DRBs), Mobility, QoSmanagement, Detection of and recovery from radio link failure, NASmessage transfer etc. SDAP Mapping between a QoS flow and a data radiobearer, Marking QoS flow ID (QFI) in both DL and UL packets. PDCPTransfer of data, Header compression and decompression, Ciphering anddeciphering, Integrity protection and integrity verification,Duplication, Reordering and in-order delivery, Out-of-order deliveryetc. RLC Transfer of upper layer PDUs, Error Correction through ARQ,Segmentation and re-segmentation of RLC SDUs, Reassembly of SDU, RLCre-establishment etc. MAC Mapping between logical channels and transportchannels, Multiplexing/demultiplexing of MAC SDUs belonging to one ordifferent logical channels into/from transport blocks (TB) deliveredto/from the physical layer on transport channels, Scheduling informationreporting, Priority handling between UEs, Priority handling betweenlogical channels of one UE etc. PHY Channel coding, Physical-layerhybrid-ARQ processing, Rate matching, Scrambling, Modulation, Layermapping, Downlink Control Information, Uplink Control Information etc.

FIG. 1C is a diagram illustrating a structure of a positioning systemaccording to an embodiment of the present disclosure.

The terminal 1C-03 is connected to the LMF 1C-33 through the gNB 1C-13and the AMF 1C-23. Hereinafter, gNB is also referred to as a basestation, AMF as an access mobility function, and LMF as a locationmanagement function.

The base station provides the TRP function. AMF stores the capability ofthe terminal related to location confirmation and relays the signalingbetween the location management function and the terminal. AMF may beconnected to several base stations. One AMF can be connected to severalLMFs. The AMF may initially select the LMF for any terminal. The AMF mayselect another LMF when the terminal moves to a new cell.

The LMF manages the support of different location services for targetUEs, including positioning of UEs and delivery of assistance data toUEs.

The LMF may interact with a target UE in order to deliver assistancedata if requested for a particular location service, or to obtain alocation estimate if that was requested.

For positioning of a target UE, the LMF decides on the position methodsto be used

The positioning methods may yield a location estimate for UE-basedposition methods and/or positioning measurements for UE-assisted andnetwork-based position methods. The LMF may combine all the receivedresults and determine a single location estimate for the target UE(hybrid positioning). Additional information like accuracy of thelocation estimate and velocity may also be determined.

FIG. 1D is a diagram illustrating a protocol hierarchical structure forsignaling between a location management function and a terminalaccording to an embodiment of the present disclosure.

The terminal and LMF exchange signaling through LPP 1D-03. LPP definesvarious control messages related to positioning. The LPP control messageis included in the NAS 1D-13 message and delivered to the AMF, and theAMF delivers the LPP control message included in the NAS message to theLMF.

LPP is a protocol applied to both LTE and NR. Hereinafter, LPP is alsocalled positioning protocol.

FIG. 2A shows the types of positioning method.

The positioning methods are GNSS positioning 2A-01, OTDOA positioning2A-05, Barometric pressure sensor positioning 2A-03, DL-AoD positioning2A-07, DL-TDOA positioning 2A-09, UL-TDOA positioning 2A-11, etc.

GNSS positioning and barometric pressure sensor positioning arepositioning methods independent of radio access technology, OTDOApositioning is a positioning method using an LTE downlink signal, andDL-AoD positioning and DL-TDOA positioning are positioning methods usinga specific NR downlink signal. The specific NR downlink signal is apositioning reference signal (PRS). UL-TDOA positioning is a positioningmethod using a specific NR uplink signal. The specific NR uplink signalis a sounding reference signal (SRS).

FIG. 2B is a diagram illustrating positioning assistance data.

Assistance data may be transmitted to the positioning device so thateach positioning can be performed more quickly and accurately. Theassistance data may be provided through system information ortransmitted through an LPP message. The positioning device may be aterminal or a base station.

Assistance data is transmitted while being included inassistanceDataElement (assitanceDataElement). One assitanceDataElementcontains specific information related to a specific positioning method.For example, GNSS-ReferenceTime assitanceDataElement includes referencetime information of GNSS and is transmitted through the positioning SIBcalled posSibType1-1 or delivered to the terminal through the LPPcontrol message called ProvideAssistanceData. When provided through thepositioning SIB, assitanceDataElement is mapped to a specificpositioning SIB type. GNSS-related assitanceDataElements 2B-01 to 2B-03are mapped to positioning SIB type 1 and positioning SIB type 2.OTDOA-related assitanceDataElement 2B-05 is mapped to positioning SIBtype 3, barometric pressure sensor positioning-relatedassistanceDataElement 2B-07 is mapped to positioning SIB type 4, andDL-AoD and DL-TDOA-related assistanceDataElement 2B-11 are mapped withpositioning SIB type 6. Most of the assistanceDataElements areimmediately applicable upon receipt. However, specific information, suchas PRS-related assistance data, can be divided into those that areimmediately applicable and those that are applicable when apredetermined condition is met that are transmitted through the SIB. Forexample, NR-DL-PRS-AssistanceData 2B-13 includes assistance data that isapplied immediately, and NR-DL-PRS-ConditionalAssistanceData 2B-15includes assistance data that is applied when a predetermined conditionis satisfied or is selectively applied.

Assistance data immediately applicable is called type 1 assistance data,and assistance data applicable when predetermined conditions are met iscalled type 2 assistance data.

FIG. 2C is a diagram illustrating the structure ofNR-DL-PRS-AssistanceData.

Definitions of each type of IEs used in FIG. 2C follow specification37.355, unless otherwise defined.

NR-DL-PRS-AssistanceData provides information on PRS as assistance datafor DL-TDOA or DL-AOD. NR-DL-PRS-AssistanceData is provided to theterminal through positioning SIB type 6-1 or throughProvideAssistanceData.

One NR-DL-PRS-AssistanceData 2C-01 is composed of onenr-DL-PRS-ReferenceInfo 2C-03 and one nr-DL-PRS-AssistanceDataList2C-05.

The nr-DL-PRS-Referencelnfo 2C-03 provides information on the identifierand frequency of the TRP that provides a reference fornr-DL-PRS-SFN0-Offset or dl-PRS-ResourceSlotOffset, etc.

The nr-DL-PRS-AssistanceDataList2C-05 is composed of a plurality ofNR-DL-PRS-AssistanceDataPerFreq2C-07. OneNR-DL-PRS-AssistanceDataPerFreq 2C-07 provides information on PRSprovided at a specific frequency, and is composed ofnr-DL-PRS-PositioningFrequencyLayer 2C-09 andnr-DL-PRS-AssistanceDataPerFreq 2C-11.NR-DL-PRS-AssistanceDataPerFreq2C-07 and nr-DL-PRS-AssistanceDataPerFreq2C-11 are different IEs.

The nr-DL-PRS-AssistanceDataPerFreq 2C-11 is composed of a plurality ofNR-DL-PRS-AssistanceDataPerTRP 2C-13. Thenr-DL-PRS-PositioningFrequencyLayer 2C-09 is common information appliedto a plurality of NR-DL-PRS-AssistanceDataPerTRP 2C-13. This is composedof information such as the subcarrier interval, the bandwidth of the PRSresource, the PRB from which the PRS resource starts. OneNR-DL-PRS-AssistanceDataPefTRP 2C-13 provides information on PRSprovided by a specific TRP. TRP may be a cell.

NR-DL-PRS-AssistanceDataPerTRP 2C-13 consists of information commonlyapplied to multiple nr-DL-PRS-ResourceSet 2C-17 and multiplenr-DL-PRS-ResourceSet 2C-17. The. Information commonly applied to theplurality of nr-DL-PRS-ResourceSets 2C-17 includes dl-PRS-ID, a cellidentifier corresponding to the TRP and the time offset of the SFN #0slot #0 for the given TRP with respect to SFN #0 slot #0 of theassistance data reference.

One nr-DL-PRS-ResourceSet 2C-17 consists of one dl-PRS-ResourceList2C-19, and dl-PRS-ResourceList 2C-19 consists of a plurality ofdl-PRS-Resources.

One dl-PRS-Resource has an identifier, code sequence information appliedto the corresponding PRS, and the starting slot of the DL-PRS Resourcewith respect to the corresponding DL-PRS-Resource Set Slot Offset andQCL information (beam information) of the corresponding PRS.

The PRS-ResourceSet is composed of a plurality of PRSs using the samefrequency resource, and is a set of PRS resources grouped for beamsweeping.

Consequently, one nr-DL-PRS-AssistanceDataList 2C-05 includes assistancedata for a plurality of frequencies. The assistance data for eachfrequency includes assistance data for a plurality of TRPs. Theassistance data for each TRP may provide information on a plurality ofDL-PRS-ResourceSets. One DL-PRS-ResourceSet is composed of a pluralityof DL-PRS-Resources. The terminal may perform positioning measurement bymeasuring the plurality of DL-PRS-Resources indicated in thenr-DL-PRS-AssistanceDataList 2C-05.

NR-DL-PRS-AssistanceData is assistance data that is applied immediately.DL-PRS included in NR-DL-PRS-AssistanceData are continuously transmittedfrom the time point when the terminal receives NR-DL-PRS-AssistanceDatauntil the terminal stops measuring positioning using DL-PRS, and theterminal immediately use the immediately applied assistance data whenpositioning measurement using the assistance data is necessary.

FIG. 2D is a diagram illustrating the structure ofPRS-ConditionalAssistanceData.

The PRS-ConditionalAssistanceDataSet (hereinafter, conditionalassistance data set) 2D-01 is composed of aPRS-ConditionalAssistanceDataList 2D-03 including a plurality ofPRS-ConditionalAssistanceData 2D-05 (hereinafter, conditional assistancedata). Each conditional assistance data 2D-05 includesPRS-AssistanceData 2D-13 (hereinafter, assistance data) that iscurrently being transmitted or that can be started when a terminalrequests it.

The conditional assistance data set includes type 2 assistance data andis provided to the terminal through positioning SIB type 6-4 or throughProvideAssistanceData. Positioning SIB type 6-1 includes only one type 1assistance data 2C-01, and positioning SIB type 6-4 includes one or moretype 2 assistance data 2D-13.

conditional assistance data 2D-05 is composed ofPRS-ConditionalAssistanceDataId 2D-07 (hereinafter assistance data id),PRS-ConditionalAssistanceDataStatus 2D-09 (hereinafter assistance datastatus), PRS-ConditionalAssistanceDataValidity 2D-11 (assistance datavalidity), ReportConfig (hereinafter, Report Configuration), andPRS-AssistanceData 2D-13 (hereinafter, assistance data).

The assistance data id 2D-07 is an identifier of the related conditionalassistance data 2D-05 or the related assistance data 2D-13 and is aninteger between 0 and 15.

The assistance data status 2D-09 is 1-bit information indicating whetherthe related assistance data 2D-13 is being transmitted (or provided).The fact that the assistance data 2D-13 is being transmitted means thatthe PRSs specified in the assistance data 2D-13 are currently beingtransmitted. If the assistance data status related to the assistancedata exists (or the assistance data status is set to the first value),the terminal determines that the PRSs specified in the assistance dataare currently being transmitted and performs the necessary operation. Ifthe assistance data status related to the assistance data does not exist(or if the assistance data status is set to the second value), theterminal determines that the PRSs specified in the assistance data arenot currently being transmitted. The terminal if necessary, requests theLMF to start transmission of the PRS

The assistance data validity 2D-11 indicates under what conditions therelevant conditional assistance data 2D-05 or the relevant assistancedata 2D-13 are valid. Alternatively the assistance data validityindicates which conditions to be fulfilled for UE to initiatemeasurement on the relevant PRS and to report measurement results. Theassistance data validity 2D-11 may include an NR CGI (Cell GlobalIdentifier) List or time interval information. The time intervalinformation is composed of the first time point and the second timepoint. In the terminal, if the NR CGI of the current cell belongs to theNR CGI List, and the current time expressed in UTC (Universal CoordinateTime) belongs to the time interval information expressed in the firsttime point and the second time point, the related conditional assistancedata 2D-05 or related assistance data 2D-13 is considered valid. If theassistance data status 2D-09 of the conditional assistance data 2D-05determined to be valid is set to ‘available’, ‘transmit’ or ‘broadcast’,the terminal performs positioning measurement for the related PRS andreport measurement results to the LMF. If the assistance data status2D-09 of the conditional assistance data 2D-05 determined to be valid isset to ‘unavailable’, ‘not transmitted’, or ‘non-broadcast’, theterminal requests LMF to activate the conditional assistance data 2D-05.Activation of the conditional assistance data means that the PRSsspecified in the conditional assistance data are transmitted.

The conditional assistance data set 2D-01 may be provided through apositioning SIB or may be provided through an LPP control message. Theassistance data status 2D-09 is included only in the conditionalassistance data set 2D-01 provided through the positioning SIB, and theassistance data validity is included only in the conditional assistancedata set provided through the LPP control message. Alternatively,assistance data status is used only for type 2 assistance data providedthrough positioning SIB, and assistance data validity is used only fortype 2 assistance data provided through assistanceDataProvide.

ReportConfig 2D-12 (hereinafter Report Configuration) is parametersrelated to positioning measurement result reporting and consists ofmaxDL-PRS-RSTD-MeasurementsPefTRPPair andtimingReportingGranularityFactor. maxDL-PRS-RSTD-MeasurementsPefTRPPairindicates the maximum number of. DL-PRS RSTD measurements for downlinkPRS RSTD (Reference Signal Time Difference).timingReportingGranularityFactor indicates recommended reportinggranularity for the DL RSTD measurements.

The terminal reports the measurement result according to the aboveReportConfig when the validity condition of the conditional assistancedata is met.

The assistance data 2D-13 of the conditional assistance data 2D-05 is anIE having the same structure as the PRS-AssistanceData 2C-01.

The conditional assistance data is classified into conditionalassistance data1 received through the positioning SIB and conditionalassistance data2 received through the LPP control message. Theassistance data status IE is essentially present in conditionalassistance data1, but the assistance data status IE does not exist inconditional assistance data2. In conditional assistance data2,assistance data validity exists, but in conditional assistance data1,data validity condition does not exist.

The purpose of conditional assistance data1 is to inform the terminal ofPRSs in which transmission can be activated in the corresponding cell.The terminal may determine the PRSs required for its own positioningmeasurement among the PRSs indicated in conditional assistance data1,and may request the LMF to activate the corresponding conditionalassistance data.

The purpose of conditional assistance data2 is to inform the terminal ofPRSs to be measured when a predetermined condition is met. The terminalmay measure the PRSs that satisfy the condition among the PRSs specifiedin conditional assistance data2 and report the results to the LMF.

FIG. 2E is a diagram illustrating a system information acquisitionprocess.

System Information Block (hereinafter referred to as SIB) includesgeneral SIB and positioning SIB. Types of general SIB include SIB1,SIB2, SIB3, SIB4, SIB5, SIB6, SIB7, SIB8, and SIB9. SIB1 includesinformation related to scheduling of other system information and radioresource configuration information commonly applied to all terminals.SIB2 includes cell reselection information. SIB3 includes informationabout neighboring cells for intra-frequency cell resection. SIB4includes information for inter-frequency cell resection. SIB5 includesE-UTRA frequency information and the like for inter-RAT cellreselection. SIB6 includes ETWS (Earthquake Tsunami Warning System) mainnotification. SIB7 includes the ETWS sub-notification. SIB8 containsCMAS notifications. SIB9 includes information related to GPS time andCoordinated Universal Time (UTC).

The assistance data mapped with the type of positioning SIB is as shownin FIG. 2B.

One or a plurality of SIBs having the same transmission period areincluded in one system information (System Information, SI) andtransmitted. scheduling information of SI related to general SIB isindicated in SI scheduling Information. The scheduling information ofthe SI related to the positioning SIB is indicated in the positioning SIscheduling Information. SI scheduling Information and positioning SIscheduling Information are included in SIB1.

The SI scheduling Information includes one or more schedulinginformation and one SI window length. The scheduling informationconsists of SI broadcast status, SI periodicity, and SIB mappinginformation. SI broadcast status indicates whether the corresponding SImessage is being broadcast. SI periodicity is the period of thecorresponding SI message. The SI window length is the length of the SIscheduling window. The SIB mapping information consists of one or aplurality of SIB type information. The SIB type information includestype information indicating one of sibType2, sibType3, sibType4,sibType5, sibType6, sibType7, sibType8, sibType9, sibType10, sibType11,sibType12, sibType13, and sibType14, and a value tag indicating one ofintegers between 0 and 31.

The positioning SI scheduling Information is composed of one or morepositioning scheduling information and the like. The positioningscheduling information consists of positioning SI broadcast status,positioning SI periodicity, and positioning SIB mapping information. Thepositioning SI broadcast status indicates whether the correspondingpositioning SI message is being broadcast. The positioning SIperiodicity is the period of the positioning SI message. The positioningSIB mapping information consists of one or a plurality of positioningSIB type information. positioning SIB type information consist of a typeinformation indicating one of posSibType1-1, posSibType1-2,posSibType1-3, posSibType1-4, posSibType1-5, posSibType1-6,posSibType1-7, posSibType1-8, posSibType2-1, posSibType2-2,posSibType2-3, posSibType2-4, posSibType2-5, posSibType2-6,posSibType2-7, posSibType2-8, posSibType2-9, posSibType2-10,posSibType2-11, posSibType2-12, posSibType2-13, posSibType2-14,posSibType2-15, posSibType2, posSibType2-17, posSibType2-18,posSibType2-19, posSibType2-20, posSibType2-21, posSibType2-22,posSibType2-23, posSibType3-1, posSibType4-1, posSibType5-1,posSibType6-1, posSibType6-2, posSibType6-2, posSibType6-3 andposSibType6-4.

In step 2E-11, the terminal 2E-01 receives SIB1 from the base station2E-03.

SI scheduling Information of SIB1 is set as in 2E-13. The positioning SIscheduling Information of SIB1 is set as in 2E-15.

SI with SI broadcast status set to being broadcast and positioning SIwith positioning SI broadcast status set to being broadcast aretransmitted according to the order included in SI scheduling Informationand positioning SI scheduling Information.

For example, it is transmitted in the order of the first SI, the secondSI, and the first positioning SI.

SI and positioning SI are transmitted within the SI scheduling windowand the positioning SI scheduling window. The length of the SIscheduling window and the length of the positioning SI scheduling windoware determined by the SI window length of SI scheduling Information.

In step 2E-17, the terminal receives the first SI in the SI schedulingwindow for the first SI. The first SI contains only SIB2 as shown in2E-13. As shown in 2E-19, the first SI includes one IE calledsib-TypeAndInfo, and sib-TypeAndInfo includes SIB2.

In step 2E-21, the terminal receives the second SI in the SI schedulingwindow for the second SI. The second SI denotes SIB3 and SIB4 as shownin 2E-13. As shown in 2E-23, the second SI includes two sib-TypeAndInfoIEs, the first sib-TypeAndInfo includes SIB3, and the secondsib-TypeAndInfo includes SIB4.

In step 2E-25, the terminal receives the first positioning SI in thepositioning SI scheduling window for the first positioning SI. The firstpositioning SI includes positioning SIB 6-1 and positioning SIB 6-2 asshown in 2E-15. As shown in 2E-27, the first positioning SI includes twoposSIB-TypeAndInfo IEs, the first posSIB-TypeAndInfo includespositioning SIB6-1, and the second posSIB-TypeAndInfo includespositioning SIB6-2.

As shown in 2E-29, one positioning SIB is composed of value tag2,expiration time, and assistanceDataElement. value tag2 indicates one ofintegers between 0 and 63 and indicates whether broadcast assistancedata has been changed. value tag2 is set by LMF. The expiration timeindicates the time point at which the contents of the broadcastassistance data expire in UTC. assistanceDataElement is a fieldcontaining actual assistance data.

General SIB indicates one of the integers between 0 and 31, and thechange is indicated by the value tag set by the base station. Thepositioning SIB indicates one of the integers between 0 and 63 and valuetag2 set by the LMF. indicates whether the change has been made or not.Value tag is included in SIB1 and broadcast, and value tag2 is includedin positioning SI and broadcast.

As shown in 2E-15, the second positioning scheduling information is notbroadcast. The terminal performs a system information request procedureto receive non-broadcast positioning scheduling information.

The terminal should always store valid system information. The terminalmaintains the validity of the system information by reacquiring thesystem information when a predetermined event occurs.

When the short message included in the DCI addressed to the P-RNTIindicates systemInfoModification, the terminal receives SIB1, determinesthe first type SIBs in which the value tag is changed, and receive thefirst type SIBs in which the value tag is changed and store it. Theterminal receives and stores positioning SIs including the second typeSIB again without considering the value tag. First type SIB is a generalSIB, and second type SIB is a positioning SIB.

When 3 hours have elapsed since the terminal successfully received thefirst type SIB, the terminal discards the first type SIB and initiates aprocedure for acquiring the SI including the first type SIB.

When the terminal successfully receives the second type SIB, it storesthe second type SIB. Then, in a systemInfoModification period startingjust before the expiration time of the second type SIB, terminal startsa procedure for acquiring the SI including the second type.

The systemInfoModification period is a time interval that occurssequentially. During one systemInfoModification period, systeminformation cannot be changed. When it is necessary to change the systeminformation, the base station transmits new system information from thetime point at which the next systemInfoModification period starts.

FIG. 2F is a diagram illustrating a system information requestprocedure.

The terminal can request system information that is not broadcast byusing the RRC control message. The RRC_IDLE terminal or RRC_INACTIVEterminal transmits positioning system information request1, and theterminal in RRC_CONNECTED state transmits positioning system informationrequest2.

In step 2F-11, the RRC_IDLE terminal or RRC_INACTIVE terminal transmitspositioning system information request1, which is an RRC control messagefor requesting positioning system information, to the base station. Thepositioning system information request1 includes the requestedpositioning SI list. The requested positioning SI list is a list of SImessages requested by the terminal to be provided to the base station.The requested SI list is a 32-bit bitmap. Each bit of the requestedpositioning SI list corresponds to each entry according to the order ofthe entries included in the positioning SI scheduling Information. Forexample, the first bit corresponds to the first positioning SI of thepositioning SI scheduling information.

In step 2F-13, the RRC_CONNECTED terminal transmits positioning systeminformation request2, which is an RRC control message for requestingpositioning system information, to the base station. The positioningsystem information request2 includes the requested positioning SIB list.The requested positioning SIB list is a list of positioning SIBsrequested by the terminal to be provided to the base station, andincludes a plurality of positioning SIB type information. Thepositioning SIB type information indicates the type of positioning SIBrequested by the terminal.

In step 2F-15, the terminal that has transmitted the positioning systeminformation request1 or positioning system information request2 receivesSIB1 from the base station. The terminal checks whether the requestedpositioning SI or SI including the positioning SIB is broadcast.

In step 2F-17, the terminal receives the positioning SI requested by theterminal or the positioning SI including the positioning SIB requestedby the terminal.

Positioning system information request1 is transmitted via SRB0 andCCCH. The positioning system information request2 is transmitted viaSRB1 and DCCH. Since the size of the control message transmitted throughthe CCCH is limited, positioning system information request1 reduces thesize of transmitted information by indicating the requested SI typeinformation in a bitmap format instead of directly indicating it. On theother hand, since a relatively large message can be transmitted throughthe DCCH, the positioning system information request2 directly indicatesthe requested positioning SIB.

FIG. 2G is a diagram illustrating the structure of an uplink MAC PDUincluding an inactive positioning measurement result.

The uplink MAC PDU including the inactive positioning measurement resultconsists of three MAC subPDUs. The MAC SDU (the first SDU) 2G-15including the ResumeRequest message belonging to SRB0 is located at thefront of the MAC PDU 2G-11, and the MAC SDU (the second SDU) includingthe LPP segment message belonging to SRB2 (the second SDU) 2G-19 islocated next. The first BSR 2G-27 is located at the rearmost part. Thatis, the first MAC subPDU including SRB0 data, the second MAC subPDUincluding SRB2 data, and the third MAC subPDU including the first BSRare included in the order. The MAC sub-header of the first MAC subPDUand the third MAC subPDU consists of two reserved bits and an LCIDfield. The MAC sub-header of the second MAC subPDU consists of onereserved bit, an F field, an LCID field, and an L field. This is so thatthe base station receiving the MAC PDU processes the ResumeRequestfirst, so that the MAC PDU is recognized as a MAC PDU related to thesmall data transfer procedure as quickly as possible. The remaining part2G-15 excluding the MAC sub-header in the first MAC subPDU and theremaining part 2G-27 excluding the MAC sub-header in the third MACsubPDU are plain text that is not ciphered. In the second MAC subPDU,the remaining part 2G-19 except for the MAC sub-header includes dataciphered with a predetermined security key. The MAC sub-header is notciphered. The reason for locating the MAC subPDUs as described above isthat the first MAC subPDU and the second MAC subPDU include dataprocessed by RRC, and the third MAC subPDU includes data processed byMAC, so it is to facilitate the processing operation of the terminal bylocating the unciphered data first and locating the ciphered data later.

FIG. 2H is a diagram illustrating the structure of a buffer statusreport MAC CE.

The first BSR MAC CE consists of one logical channel group identifierfield 2H-01 and one first buffer size field 2H-03. The logical channelgroup identifier field 2H-01 has a 3-bit size and indicates one of thelogical channel group identifiers between 0 and 7. The first buffer sizefield 2H-03 has a size of 5 bits and indicates one of the first buffersize indexes from 0 to 31. The first buffer size index 0 means thatthere is no data available for transmission in logical channelsbelonging to the corresponding logical channel group. The first buffersize index 31 means that the amount of data for transmission of thelogical channels belonging to the corresponding logical channel group isgreater than the 30th first buffer size. The first buffer size index 1means that the amount of data for transmission of logical channelsbelonging to the corresponding logical channel group is greater than 0and less than or equal to the first buffer size. The first buffer sizeindex n (2<=n<=30) indicates that the amount of data for transmission ofthe logical channels belonging to the corresponding logical channelgroup is greater than the n−1st buffer size and less than or equal tothe nth first buffer size. The 30 first buffer sizes are defined in thestandard.

The second BSR MAC CE consists of 8 LCGi bits 2H-11 and a plurality ofthe second buffer size fields 2H-13. The LCGi bit indicates whether thesecond buffer size field for logical channel group i exists. Forexample, it indicates whether the second buffer size field for LCG1logical channel group 1 exists. If this field is 1, the second buffersize field for the corresponding LCG exists. The second buffer sizefield has an 8-bit size and indicates one of the second buffer sizeindexes between 0 and 255. The second buffer size index 0 means thatthere is no data available for transmission in logical channelsbelonging to the corresponding logical channel group. The second buffersize index 254 means that the amount of data for transmission of thelogical channels belonging to the corresponding logical channel group isgreater than the size of the 253-th second buffer size. The secondbuffer size index 1 means that the amount of data for transmission ofthe logical channels belonging to the corresponding logical channelgroup is greater than 0 and less than or equal to the first secondbuffer size. The second buffer size index n (2<=n<=253) indicates thatthe amount of data for transmission of the logical channels belonging tothe corresponding logical channel group is greater than the (n−1)^(th)buffer size and less than or equal to the n^(th) buffer size. The secondbuffer size index 255 is not used. The 252 second buffer sizes aredefined in the specification.

The first BSR MAC CE is referred to as a BSR to which the first formatis applied or the first format BSR. The second BSR MAC CE is referred toas a BSR to which the second format is applied or the second format BSR.

Logical channel group is configured when logical channel is configured.A logical channel and a logical channel group are configured with an RRCcontrol message.

In general, a buffer size index reflecting the amount of data availablefor transmission of the RLC layer and the amount of data available fortransmission of the PDCP layer is set in buffer size field.

FIG. 3A is a diagram illustrating the overall operation of a terminal, abase station, and an LMF.

In step 3A-11, the terminal selects a NR cell and camps on it. Theterminal may select an NR cell in which downlink reference signalreceived power and downlink reference signal received quality exceed apredetermined threshold. The terminal does not consider neighboring cellinformation included in the System Information Block in cell selection.

In step 3A-13, the terminal receives system information from the basestation in the selected NR cell. The terminal receives the MIB first,and receives SIB1 based on the information of the MIB. The terminalreceives the remaining system information by referring to the schedulinginformation of SIB1.

In steps 3A-15, the terminal establishes an RRC connection with the basestation. The terminal and the base station exchange RRCRequest messages,RRCSetup messages, and RRCSetupComplete messages through the randomaccess process. When the terminal receives the RRCSetup message from thebase station, the RRC connection is established. A terminal that hasestablished an RRC connection may perform a positioning preparationprocedure and a positioning execution procedure with a base station orLMF.

The positioning preparation procedure consists of a UE capabilityreporting phase 3A-17 and an assistance data delivery phase 3A-19. Thepositioning execution procedure 3A-21, 3A-23 consists of a terminal anda base station performing positioning measurement using an uplink signaland a downlink signal and reporting it to the LMF. The UE capabilityreporting phase is performed only in the RRC connected state, but theassistance data delivery phase and the positioning execution proceduremay be performed not only in the RRC connected state but also in the RRCinactive state.

When the terminal receives assistance data and report configuration fromthe base station or the LMF, it measures for positioning based on theassistance data, and reports the measurement result to the LMF based onthe report configuration. The terminal may receive the first typeassistance data in assistanceDataProvide and may receive ReportConfiguration in positioningDataRequest. Upon receiving thepositioningDataRequest, the terminal performs positioning measurementbased on the assistance data of the first type assistance data ofassistanceDataProvide and reports the measurement result to the LMFbased on the Report Configuration of positioningDataRequest. Theterminal can receive the second type assistance data including ReportConfiguration and assistance data validity in one assistanceDataProvide.When the validity of the assistance data is satisfied, the terminalperforms the measurement for positioning based on the second typeassistance data of the assistanceDataProvide and reports the measurementresult to the LMF based on the Report Configuration of the sameassistanceDataProvide.

FIG. 3B is a diagram illustrating a terminal capability reportingprocedure.

In step 3B-11, the first base station 3A-03 instructs capabilityreporting by transmitting a UECapabilityEnquiry RRC message to theterminal 3A-01.

In step 3B-13, the terminal reports the capability by sending aUECapabilityInformation RRC message to the first base station.UECapabilityInformation includes the first capability information andthe third capability information. The base station may determine thepositioning measurement configuration for the terminal by referring tothe first capability information and the third capability information.

In step 3B-15, the first base station delivers the first capabilityinformation and the third capability information to the AMF 3A-04, andin step 3B-17, the AMF stores the first capability information and thethird capability information for future use.

In step 3B-21, the first LMF 3A-05 instructs capability reporting bysending an LMF message called requestCapabilities to the terminal. Themessage includes information indicating for which positioning method theterminal should report capability.

In step 3B-23, the terminal reports the capability by sending the LMFmessage provideCapabilities to the first LMF. provideCapabilitiesincludes the second capability information and the third capabilityinformation. The first LMF refers to the second capability informationand the third capability information to instruct positioning measurementfor the terminal and provides assistance data required by the terminal.

In step 3B-25, the first LMF transfers the second capability informationand the third capability information to the AMF, and in step 3B-27, theAMF stores the second capability information and the third capabilityinformation for future use.

At future, the terminal establishes an RRC connection at the second basestation 3A-07. When the location service for the terminal is started,the AMF provides the first capability information and the thirdcapability information to the second base station in step 3B-31, insteadof the base station and the LMF directly acquiring the relevantcapability information to the terminal, and in step 3B-33, the AMFprovides the stored second capability information and the thirdcapability information to the second LMF.

The first capability information is capability information that theterminal reports to the base station through the RRC control message. Itis capability information that LMF does not require only base stationrequires. The following IEs are applicable. The first capabilityinformation is information necessary for the base station to establishpositioning measurement and is information about capability closelyrelated to the radio interface.

The first capability information1: it indicates whether the UE supportsparallel transmission of SRS and PUCCH/PUSCH

The first capability information2: Information indicating whether theterminal supports SRS for positioning in the connected state (indicatingsupport of SRS for positioning in RRC_CONNECTED) it is defined for eachband of the band combination (or defined within the band combination) Itis reported as part of the band combination specific capabilityinformation. The terminal reports band specific capability informationfor each band it supports. The terminal reports band combinationspecific capability information that is valid only for the bandcombination within the band combination for each band combinationsupported by the terminal. Whether the connection state positioning SRSis supported is indicated for each band in the band combination. Forexample, if the terminal supports band A, band B, and band combination[A, B], the terminal reports to the base station band A specificcapability information applied to band A and band B specific capabilityinformation applied to band B and band A capability information in theband combination [A,B] and band B capability information in the bandcombination [A,B]. Terminal reports as band capability information ofthe band combination whether positioning SRS is supported in connectedmode

The first capability information3: it indicates the maximum number ofconfigured pathloss reference RSs for PUSCH/PUCCH/SRS for pathlossreference RS update.

The first capability information4: it indicates measurement gappattern(s) optionally supported by the UE for PRS measurement.

The first capability information5: it indicates support of small datatransfer via SRB2.

The second capability information is capability information that theterminal reports to the LMF through the LPP control message. It is thecapability information that LMF needs and base station does not need.The following IEs are applicable. The second capability information isinformation required for the LMF to establish positioning measurementand positioning report. It is information on capability closely relatedto the positioning function.

The second capability information1: It indicate several positioningmodes using a bit map. positioning mode information indicates a modesupported by the UE among UE-assisted and LMF-based mode, LMF-basedmode, LMF-assisted and UE based mode, UE based mode and UE standalonemode.

The second capability information2: It indicates the target device's LPPmessage segmentation capabilities. If bit0 is 1, it indicates that thetarget device can receive the segmented LPP message. If bit1 is 1, itindicates that the target device can transmit a segmented LPP message.

The second capability information3: It indicates whether the targetdevice can perform positioning measurement using PRS for a predeterminedpositioning method in an inactive state. The predetermined positioningmethod may be, for example, DL-AoD or DL-TDOA. That is, it indicateswhether the terminal can measure PRS in the inactive state.

The second capability information4: It indicates whether the targetdevice can report the positioning measurement result in the inactivestate.

The third capability information is capability information that theterminal reports to the LMF through the LPP control message and to thebase station through the RRC control message. It is the capabilityinformation required by both the LMF and the base station, and thefollowing IEs are applicable.

The third capability information1: It indicates support of SRS forpositioning in RRC_INACTIVE. It is defined per band and reported as partof band specific capability information.

The third capability information2: It is outer loop power controlrelated information. It indicates whether the UE supports OLPC for SRSfor positioning.

The third capability information3: It indicates whether the UE supportsspatial relations for SRS for positioning.

The first capability information2 (indicating whether positioning SRS issupported in CONNECTED state) is reported to base station per bandcombination (or per feature set). The third capability information1(indicating whether positioning SRS is supported in INACTIVE state) isreported per band to base station and to LMF. The definition ofFeatureSet can be referred to 3GPP specification 38.331 and 38.306.

Capability information on positioning SRS in INACTIVE state is reportedboth to base station and to LMF. Capability information on PRS inINACTIVE state is reported to LMF only.

FIG. 3C is illustrating assistance data delivery phase.

The assistance data is classified into immediate assistance data (firsttype assistance data) and conditional assistance data (second typeassistance data). The base station may provide assistance data using thepositioning SIB. The LMF sets the contents of the assistance dataincluded in the positioning SIB. The LMF can provide assistance data tothe terminal using the LPP control message. The terminal may acquireassistance data through system information in the idle state as in steps3A-13 or may acquire assistance data through system information afterRRC connection state transition 3A-15. When the location service isstarted, the terminal may initiate a procedure for obtaining assistancedata. The location service may be started regardless of the RRC state ofthe terminal.

In step 3C-11, the terminal receives SIB1 from the base station. Theterminal stores SI scheduling Information and positioning SI schedulingInformation.

The terminal transitions to the connected state through steps 3A-15 and3A-17 and performs the terminal capability reporting step. If thelocation service is started, the terminal performs steps 3A-19 to obtainassistance data.

In step 3C-13, the terminal receives the SI including the positioningSIB from the base station and determines whether required assistancedata is provided in the corresponding cell. Required assistance datameans assistance data for a positioning method supported by a terminalor assistance data for a positioning method to be used in a disclosedlocation service. The terminal determines, through the positioning SIscheduling information of SIB1, the required assistance data directly orindirectly provided from the corresponding cell and the requiredassistance data not provided from the corresponding cell. The assistancedata currently being transmitted from the corresponding cell, that is,the assistance data of the positioning SIB in which the positioning SIbroadcast status is set to being broadcast, is assistance data directlyprovided from the corresponding cell. Assistance data that is notcurrently transmitted from the corresponding cell but may be transmittedin the future, that is, the assistance data of the positioning SIB inwhich the positioning SI broadcast status is set to non-broadcast, isassistance data that is indirectly provided from the corresponding cell.The terminal receives the positioning SI including the positioning SIBprovided directly in step 3C-13 as follows.

-   -   1: Determining the time interval in which the positioning        SI/positioning SIB can be transmitted based on the SI window        length in the SI scheduling information and positioning SIB        mapping information and the order of the SI scheduling        information in the positioning SI scheduling information        obtained from SIB1.    -   2: Monitoring SI-RNTI in the time interval    -   3: Receive a MAC PDU scheduled through SI-RNTI in the time        interval    -   4: Acquire positioning SI included in the MAC PDU

In order to obtain the necessary positioning SIB provided indirectly,the terminal generates a positioning system information request2requesting the positioning SIB to the base station.

In step 3C-15, the terminal sends positioning system informationrequest2 to the base station. The terminal sets the requestedpositioning SIB list as follows.

-   -   1: Identifying the positioning SI mapped with the required        positioning SIB    -   2: Identifying the positioning SI in which the positioning SI        broadcast status is non-broadcast among the positioning SIs    -   3: Determining the positioning SIB mapped to the positioning SI    -   4: Including the positioning SIB type information in the        requested positioning SIB list

That is, the terminal includes, in the requested positioning SIB list, apositioning SIB mapped to a positioning SI in which the positioning SIbroadcast status is set to non-broadcast among the required positioningSIBs.

In step 3C-17, the terminal receives the requested indirect positioningSIB/positioning SI from the base station. The indirect positioning SIBincludes immediate assistance data1. The immediate assistance data1 maybe, for example, GNSS-related assistance data included in positioningSIB1-x or positioning SIB2-x. Alternatively, immediate assistance data1may be NR-DL-PRS-AssistanceData included in positioning SIB 6-1.

In step 3C-21, the terminal receives the indirect positioningSIB/positioning SI requested from the base station. The indirectpositioning SIB includes conditional assistance data1. The conditionalassistance data1 may be, for example, a conditional assistance data setincluded in positioning SIB 6-4.

The base station includes the immediate assistance data and theconditional assistance data in different positioning SIBs and maps thepositioning SIB corresponding to the immediate assistance data and thepositioning SIB corresponding to the conditional assistance data to thedifferent positioning SIs. Through this, terminals requiring onlyimmediate assistance data and terminals requiring only conditionalassistance data can receive only required. In addition, assistance datacan be provided more flexibly, for example, immediate assistance data istransmitted directly to positioning SIB/direct positioning SI andconditional assistance data is transmitted to indirect positioningSIB/indirect positioning SI.

In step 3C-23, the terminal transmits an LPP message calledrequestAssistanceData requesting assistance data to the base station.The LPP message is delivered to the LMF through the base station.requestAssistanceData is transmitted to the base station throughSRB2/DCCH.

RequestAssistanceData contains the fields below.

-   -   1: PCI of PCell. The LMF identifies the cell in which the        terminal is located by referring to the PCI of the PCell and        determines the assistance data valid for the cell and the        adjacent area.    -   2: Type of required assistance information. It indicates the        type of assistance data requested by the terminal. This field        indicates the relevant positioning method. For example, if this        field indicates GNSS, the LMF determines that the terminal        requests to provide GNSS-related assistance data.    -   3: Identifier of conditional assistance data1 requiring        activation. It is an identifier of conditional assistance data1        for which a terminal is desired to be activated among        conditional assistance data1 obtained through positioning SIB or        the like. The terminal indicates the assistance data id 2D-07 of        the desired conditional assistance data 2D-05 among the        plurality of conditional assistance data 2D-05 included in the        conditional assistance data set 2D-01.    -   4: Information indicating that the required (or requested)        assistance data is conditional assistance data. The terminal        includes this field if the conditional assistance data 1        received from the base station does not include the conditional        assistance data for the positioning method it wants.

In step 3C-25, the LMF transmits an LPP message calledProvideAssistanceData that provides assistance data to the terminal.ProvideAssistanceData contains the fields below.

-   -   1: immediate assistance data. Among the immediate assistance        data requested by the terminal, this is the immediate assistance        data that the LMF can provide.    -   2: Activated conditional assistance data id. The activated        conditional assistance data is indicated among the conditional        assistance data1 for which the terminal has requested        activation. It is indicated by the assistance data id.    -   3: conditional assistance data2. Among the conditional        assistance data requested by the terminal, this is the        conditional assistance data that the LMF can provide. When a        predetermined condition is met, the terminal performs        positioning measurement by applying conditional assistance data2        and reports the positioning measurement result to the LMF.    -   4: inactive positioning. Information indicating whether the        terminal should perform positioning-related operations in the        inactive state. It may be at least one of the following three        pieces of information.    -   4-1: positioning measurement continuation indicator: 1-bit        information indicating whether to continue the currently        performed positioning measurement operation after transitioning        to the inactive state.    -   4-2: conditional assistance data based positioning measurement:        1-bit information instructing to perform positioning measurement        by applying available conditional assistance data when        transitioning to an inactive state. The available conditional        assistance data may be a plurality of conditional assistance        data included in conditional assistance data1 and a plurality of        conditional assistance data included in conditional assistance        data2.    -   4-3: inactive positioning measurement method list: A list of        positioning measurement methods to be performed by the terminal        when transitioning to inactive state. It may be composed of a        bitmap in which each bit is mapped with a predetermined        positioning measurement method.

The terminal may perform positioning measurement by measuring PRSsindicated in immediate assistance data and PRSs indicated in activatedconditional assistance data1.

The terminal reports the PCI to the LMF in requestAssistanceData. TheLMF may provide conditional assistance data validity informationcomposed of multiple NR CGIs to the terminal in ProvideAssistanceData.Alternatively, the LMF may provide conditional assistance data validityinformation composed of a plurality of CellIdentity to the terminal inProvideAssistanceData. Alternatively, the LMF may provide conditionalassistance data validity information composed of a plurality of cellidentities and a plurality of base station identifier (gNB identifier)length information to the terminal in ProvideAssistanceData.

LMF considers PCI and determines which cell's assistance data to provideto the terminal. The terminal determines in which cell the assistancedata is valid by considering the cell identifier provided by the LMF.

The NR CGI consists of MCC (Mobile Country Code) and MNC (Mobile NetworkCode), which are information indicating the PLMN, and Cell Identity,which is information indicating the cell. Cell Identity has a size of 36bits, and the leftmost n bits are the base station indicator (gNBidentifier). The n has a variable size between 22 and 32 and may beknown to the terminal as separate information called base stationidentifier length information. PCI is an integer between 0 and 1007. PCIis an indicator that specifies a cell within a relatively narrow area,NR CGI is an indicator that specifies a cell globally, and Cell Identityis an indicator that specifies a cell within one PLMN.

FIG. 3D is a diagram illustrating an uplink positioning process of aninactive terminal.

In the uplink positioning process, the terminal in the RRC connectedstate receives the SRS configuration from the base station and transmitsthe SRS, the base station measures the SRS and reports the measurementresult to the LMF, and the LMF calculates the terminal's position basedon the measurement result. Although the SRS measurement can be performedby several base stations, only one base station is illustrated in FIG.3D for convenience.

In step 3D-01, the terminal receives an RRCReconfiguration messageincluding SRS configuration from the base station. The SRS configurationmay be provided for each UL BWP, and the SRS configuration consists ofone or more SRS-PosResourceSet (hereinafter, SRS positioning resourceset). One SRS positioning resource set consists of one or moreSRS-PosResource (hereinafter, SRS positioning resource).

The SRS positioning resource is defined by srs-PosResourceId (SRSpositioning resource identifier), startPosition, nrofSymbols,freqDomainShift, freqHopping, periodicityAndOffset-sp,spatialRelationInfoPos, and the like.

StartPosition and nrofSymbols indicate the start position of a symbol inwhich SRS is transmitted and the number of symbols in which SRS istransmitted in the positioning SRS slot.

FreqDomainShift and freqHopping define the frequency resource throughwhich the SRS is transmitted in relation to the frequency domain of thecorresponding BWP.

PeriodicityAndOffset-sp indicates the periodicity and the slot at whichthe positioning SRS slot starts. The positioning SRS slot means a slotin which a positioning SRS resource is configured or a slot in which apositioning SRS is transmitted.

SpatialRelationInfoPos defines a spatial domain transmission filter tobe applied to positioning SRS transmission and may be set to a downlinkreference signal index of a serving cell, an SSB index of a neighboringcell, and the like.

SRS positioning resource set consists of SRS positioning resource setidentifier, SRS positioning resource identifier list, ResourceType,alpha, p0, pathlossReferenceRS-Pos.

SRS positioning resource identifier list is the list of SRS positioningresource identifiers composing the SRS positioning resource set.

ResourceType indicates one of“periodic” and “semi-persistent” and“aperiodic”. In the present disclosure, a semi-persistent SRSpositioning resource set will be described as an example. For SRSpositioning resource set of which ResourceType is indicated assemi-persistent, SRS transmission of SRS positioning resource set startsonly after a specific control message instructs transmission.

Alpha, p0 and pathlossReferenceRS-Pos are parameters for transmissionpower control of positioning SRS. alpha and p0 are power offsets thatare added when determining positioning SRS transmission power, andpathlossReferenceRS-Pos provides path loss when determining positioningSRS transmission power. is the reference signal.

In step 3D-03, the terminal receives a Positioning SRSActivation/Deactivation MAC CE instructing to start transmission of aspecific SRS positioning resource set from the base station.

The Positioning SRS Activation/Deactivation MAC CE consists of an A/Dfield, a Cell ID field, a BWP ID field, a SUL field, and a PositioningSRS Resource Set ID.

The A/D field indicates whether to activate or deactivate the indicatedSRS positioning resource set.

The Cell ID field indicates the identifier of the serving cell to whichthe SRS positioning resource set to be activated/deactivated belongs.

The BWP ID field indicates the identifier of the BWP to which the SRSpositioning resource set to be activated/deactivated belongs.

The SUL field indicates whether the MAC CE is applied to a NUL carrierconfiguration or a SUL carrier configuration. Or it indicates whetherthe activated or deactivated SRS positioning resource set is an SRSpositioning resource set of SUL or an SRS positioning resource set ofNUL.

The Positioning SRS Resource Set ID field is an identifier of the SRSpositioning resource set to be activated or deactivated.

NUL is normal uplink and SUL is supplementary uplink. One serving cellmay have only NUL or may have NUL and SUL. The SUL is configured in thelow frequency band comparing to the NUL to increase the uplink coverageof the cell.

In step 3D-05, the terminal transmits a positioning SRS in the activatedSRS positioning resource set. The terminal transmits the positioning SRSfrom SRS positioning resources belonging to the SRS positioning resourceset by applying the transmission power control parameter of the SRSresource set. The SRS positioning resources are periodically generatedaccording to periodicityAndOffset-sp.

In step 3D-07, the terminal receives the RRCRelease message from thebase station.

The base station may change the state of the terminal to RRC_INACTIVE orRRC_IDLE in consideration of the terminal's traffic condition, cell loadcondition, and RRM condition of the terminal. If the uplink positioninghas not yet been completed, the base station instructs the terminal totransition to the RRC_INACTIVE state while continuing to transmit thepositioning SRS. The base station transmits an RRCRelease messageincluding inactive SRS IE, stop condition IE, and SuspendConfig 1E tothe terminal.

The terminal stores the SRS configuration in the Inactive Access StratumContext.

The terminal receiving the message performs cell selection. At thistime, the terminal preferentially selects the first cell if it ispossible to select the first cell. If the reference signal receivedquality of the first cell is higher than a predetermined threshold, theterminal preferentially selects the first cell and camps on it. Thefirst cell is one of a serving cell in which the terminal receives theRRCRelease message, a PCell at the time point when the terminal receivesthe RRCRelease message, or a serving cell in which the SRS positioningresource set is activated. Alternatively, the first cell may be a cellbelonging to the first cell list. The first cell list includes aplurality of cell information, and each cell information includes PCIand an Absolute Radio Frequency Channel Number (ARFCN). The first celllist may be included in the RRCRelease message and transmitted to theterminal. ARFCN is defined in specification 38.101, and each AFRCNcorresponds to a specific frequency.

In step 3D-09, the terminal determines whether to continue to performpositioning SRS transmission, if so, which SRS positioning resource setto transmit. The terminal determines whether to transmit the positioningSRS in consideration of the inactive SRS IE and whether the newlyreselected cell is the first cell. The inactive SRS IE includes one ofan inactive SRS transmission continuation indicator, the first SRSresource set IE and the second SRS resource set IE. The inactive SRS IEmay also include an SRS transmission stop condition IE. The inactive SRSIE may also include an SRS transmission condition IE.

The inactive SRS transmission continuation indicator is an indicatorsupporting that the SRS positioning resource set of NUL continues totransmit and the SRS positioning resource set of SUL stops transmissionamong the currently active SRS positioning resource sets. The terminalperforms the above operation if the indicator is included.

The first SRS resource set IE consists of an identifier of an SRSpositioning resource set, a cell identifier, a BWP identifier, and thelike. After the terminal transitions to the inactive state, it transmitsthe positioning SRS by activating the SRS positioning resource setspecified by the cell identifier, the BWP identifier, and the SRSpositioning resource set identifier. The SRS positioning resource set tobe activated is limited to the SRS positioning resource set in the BWPof the NUL. In other words, when the NUL BWP and the SUL BWP having thesame BWP identifier exist, the SRS positioning resource set identifieris an identifier indicating the SRS positioning resource set in the NULBWP. The identifier of the SRS positioning resource set indicates aspecific SRS positioning resource set of a specific BWP of the NUL of aspecific serving cell, and the SRS positioning resource setcorresponding to the SRS positioning resource set identifier is definedin the SRS configuration provided for the specific BWP. Alternatively,the first SRS resource set IE may include an identifier of an SRSpositioning resource set, a cell identifier, a BWP identifier, and a SULindicator. If the SUL indicator is not included in the first SRSresource set IE, the inactive state terminal transmits a positioning SRSin the NUL, and when the SUL indicator is included in the first SRSresource set IE, the inactive state terminal transmits a positioning SRSin the SUL.

The second SRS resource set IE consists of an SRS positioning resourceset IE, a cell identifier, a BWP identifier, and the like. Aftertransitioning to the inactive state, the terminal transmits thepositioning SRS in the SRS positioning resource specified by the SRSpositioning resource set IE in the frequency domain indicated by thecell identifier and the BWP identifier. At this time, if there are twoBWPs corresponding to the BWP identifier, a BWP of NUL is selected.Alternatively, the second SRS resource set IE may include an SRSpositioning resource set IE, a cell identifier, a BWP identifier, a SULindicator, and the like. If the SUL indicator is not included in thesecond SRS resource set IE, the inactive state terminal transmits apositioning SRS in the NUL, and when the SUL indicator is included inthe second SRS resource set IE, the inactive state terminal transmits apositioning SRS in the SUL.

The SRS transmission stop condition IE defines a condition for stoppingthe transmission of the positioning SRS, which the terminal wastransmitting in the inactive state. The SRS transmission stop conditionmay be the number of positioning SRS transmissions, a time point to stoppositioning SRS transmission, and the like.

The SRS transmission condition IE defines the conditions that must besatisfied in order for the terminal to transmit the positioning SRS inthe inactive state. The SRS transmission condition may be defined as thefirst time point and the second time point. The terminal startstransmitting positioning SRS at the first time point in the inactivestate and stops transmitting positioning SRS at the second time point.The first time point and the second time point may be indicated by theSFN and subframe number of the first cell. The first time point and thesecond time point can be expressed in absolute times such as UTC.

If the newly selected cell is the first cell and the inactive SRS IEexists, the terminal transmits the positioning SRS as described aboveeven in the inactive state.

If the newly selected cell is not the first cell, the terminal removesthe SRS configuration from the inactive AS context and does not transmitthe positioning SRS in the inactive state.

In step 3D-11, the terminal periodically transmits the positioning SRSin the inactive state. The terminal continues to transmit the previouslyactivated SRS positioning resource set. Or the terminal deactivates thepreviously activated SRS positioning resource set, activates the SRSpositioning resource set indicated in the first SRS resource set IE andtransmits the SRS positioning resource set. Or the terminal deactivatesthe previously activated SRS positioning resource set, activates the SRSpositioning resource set indicated in the second SRS resource set IE andtransmits the SRS positioning resource set

The base station collects location-related measurement information byreceiving the positioning SRS transmitted by the terminal in theinactive state.

In step 3D-13, the base station transmits a MEASUREMENT RESPONSE messageincluding the SRS measurement result to the LMF. The LMF calculates theposition of the terminal using the measurement result. When positioningof the terminal is completed, the LMF notifies the base station thatpositioning is complete.

In step 3D-15, the base station receives the message POSITIONINGDEACTIVATION from the LMF and recognizes that the uplink positioning hasbeen completed.

In step 3D-17, the base station transmits a downlink control message tostop transmitting the positioning SRS of the terminal. The downlinkcontrol message may be, for example, a paging message. The base stationmay include the terminal's I-RNTI (inactive wireless network temporaryidentifier) and positioning SRS transmission stop information in thepaging message. The I-RNTI is assigned in the RRCRelease message. TheRRCRelease message allocates two I-RNTIs: a full I-RNTI and a shortI-RNTI. The terminal determines whether an I-RNTI matching its fullI-RNTI is included in the paging.

Upon receiving the paging message including its I-RNTI, the terminaldetermines whether information related to SRS transmission stop, forexample, positioning SRS transmission stop information, is included inthe paging message. The terminal performs one of the following actionsaccording to its judgment.

-   -   1: If the paging message including its I-RNTI does not contain        information related to SRS stop and inactive SRS transmission is        being performed, the terminal stops SRS transmission and        initiates the RRC connection resumption procedure.    -   2: If the paging message including its I-RNTI does not include        information related to SRS stop and inactive SRS transmission is        not being performed, the terminal initiates the RRC connection        resumption procedure.    -   3: If information related to SRS stop is included in the paging        message including its I-RNTI and inactive SRS transmission is        being performed, the terminal stops SRS transmission and does        not initiate the RRC connection resumption procedure.    -   4: If the paging message including its I-RNTI includes        information related to SRS stop and inactive SRS transmission is        not being performed, the terminal ignores the paging message and        does not initiate the RRC connection resumption procedure.

The terminal performs random access to perform a resumption procedureand transmits a predetermined uplink RRC control message.

In step 3D-19, the terminal stops inactive SRS transmission or initiatesa resumption procedure with reference to the information included in thepaging message.

A terminal in inactive state stops transmitting positioning SRS in thefollowing cases.

-   -   1: The cell selected after receiving the RRCRelease message is        not the first cell.    -   2: Reselect another cell from the first cell.    -   3: SRS transmission stop condition is satisfied.    -   4: The resumption procedure is started.    -   5: Receives a paging message indicating to stop inactive SRS        transmission.

One paging message includes a plurality of pagingRecords, and eachpagingRecord among the plurality of pagingRecords includes oneterminalidentifier field and one second information field. Among theplurality of pagingRecords, in each pagingRecord, the terminalidentifierfield is mandatory present and the second information field isoptionally present. The terminalidentifier field is set to full I-RNTIand the second information field is enumerated with a single valueindicating an SRS stop.

Optionally present IE being enumerated with a single value means thatthe single value is applied if the IE is present and the single value isnot applied if the IE is not present.

FIG. 3E is a diagram illustrating a downlink positioning process of aninactive terminal.

A terminal that has obtained immediate assistance data, conditionalassistance data1, and conditional assistance data2 through steps 3C-13to 3C-25 performs an operation related to downlink positioning by usingthe assistance data.

An operation related to downlink positioning is, for example, measuringthe reception time difference of PRSs transmitted from a plurality ofTRPs and reporting the result to the LMF, or measuring the receivedpower of PRSs transmitted from a plurality of TRPs and reporting to theLMF, etc.

In step 3E-01, the terminal generates an RRC control message calledUEAssistanceInformation to report to the base station that downlinkpositioning should be performed even in the RRC_INACTIVE state andtransmits it to the base station. The control message may include aninactive positioning2 IE indicating the type of positioning method thatthe terminal can perform in an inactive state. the control message caninclude a information requesting to configure small data transfer viaSRB2. The control message may include time pattern information of PRSfor positioning. The terminal performs steps 3E-03 if the inactivepositioning IE is included in the ProvideAssistanceData received insteps 3C-25.

In step 3E-03, the base station sends an RRCRelease message to theterminal.

The base station may change the state of the terminal to RRC_INACTIVE orRRC_IDLE in consideration of the terminal's traffic condition, cell loadcondition, and RRM condition of the terminal. If the base stationdetermines that the terminal needs to measure positioning in theinactive state, the base station may provide information related todownlink positioning measurement while instructing the terminal totransition to the RRC_INACTIVE state.

Information related to downlink positioning measurement may include, forexample, offset information for moving the paging monitoring period ofthe terminal so that the paging monitoring time interval of the terminaldoes not overlap with the PRS measurement period.

The base station can configure small data transfer through SRB2 to theterminal. The small data transfer configuration may consist of a list ofdata bearers for which small data transfer is configured, and 1-bitinformation indicating whether small data transfer can be configured toSRB2. When small data transfer is applied to SRB2, the terminal cantransmit the data of SRB2 to the base station through the small datatransfer procedure. The small data transfer procedure is a procedure inwhich the RRC_INACTIVE terminal transmits small data through the RRCconnection resumption procedure without transitioning to RRC_CONNECTED.

Upon receiving the RRCRelease message including information related todownlink positioning measurement, the terminal performs cell selection.At this time, if the reference signal received power of the second cellis greater than or equal to a predetermined threshold, the terminalpreferentially selects the second cell to camp on. The second cell maybe a serving cell receiving the RRCRelease message or a PCell at a timepoint receiving the RRCRelease message.

In step 3E-05, the terminal selecting the new cell monitors whether theassistance data validity is met. If the newly selected cell is thesecond cell, the terminal considers both conditional assistance data1and conditional assistance data2. The terminal considers onlyconditional assistance data2 if the newly selected cell is not thesecond cell.

The terminal monitors if at least one assistance data validity isfulfilled among the assistance data validity of which data status isbroadcast included in either conditional assistance data1 or conditionalassistance data2 In step 3E-06, if it is determined that the assistancedata of the conditional assistance data for which the assistance datavalidity is satisfied is determined to be valid, the terminal startsmeasuring the downlink PRSs specified in the assistance data. Theterminal measures the arrival time difference of PRSs transmitted by aplurality of TRPs. When the PRS measurement is completed, the terminalgenerates an LPP ProvideLocatinoInformation message including themeasurement result. The terminal initiates a small data transferprocedure to transmit the LPP message. If necessary, theProvideLocatinoInformation message can be segmented into a plurality ofsegments and transmitted. The ProvideLocatinoInformation messageincludes information on arrival time difference of PRSs transmitted by aplurality of TRPs, one assistance data identifier and a plurality ofdownlink positioning reference signal identifiers (DL-PRS id). Thedownlink positioning reference signal identifier is an identifier of themeasured PRSs, and the assistance data identifier is an identifier ofassistance data providing the configuration of the measured PRSs. If thePRS measurement is made based on the first type assistance data, theProvideLocatinoInformation message includes a plurality of measurementresults and a plurality of downlink positioning reference signalidentifiers. If the RRS measurement is made based on the second typeassistance data, the ProvideLocatinoInformation message includes aplurality of measurement results and a plurality of downlink positioningreference signal identifiers and one assistance data id.

In step 3E-07, the terminal transmits a ResumeRequest, an LPP segmentmessage, and a MAC PDU including a Buffer Status Report (BSR) to thebase station. The LPP segment message includes the first segment of theLPP ProvideLocatinoInformation message. The BSR includes information onthe size of the remaining segments of the LPP ProvideLocatinoInformationmessage. The ResumeRequest belongs to SRB0 and the LPP segment messagebelongs to SRB2. The ResumeRequest of SRB0 is not ciphered, the LPPsegment message of SRB2 is ciphered, and the BSR is not ciphered. Theciphering is performed with a new security key calculated through thevalue of NCC received by the terminal in the RRCRelease message and thesecurity key stored by the terminal. In principle, all RRC messages areciphered, but the RRC message of SRB0 is not ciphered because it is amessage that the base station must process without prior information.Since BSR is information processed by the MAC layer of the base station,it is not ciphered. As a result, the MAC PDU transmitted to report thepositioning measurement result in the inactive state includes three MACsubPDUs, the first MAC subPDU and the third MAC subPDU include anunciphered payload, and the second MAC subPDU includes a cipheredpayload.

The terminal reports the amount of data available for transmissionthrough the BSR. The RRC_CONNECTED terminal determines the BSR format inconsideration of the number of logical channel groups in which dataavailable for transmission exists. That is, the RRC_CONNECTED terminaluses the first BSR if the number of logical channel groups in which dataavailable for transmission is one and uses the second BSR if it is morethan one. The RRC_INACTIVE terminal determines the BSR format withoutconsidering the number of logical channel groups in which data availablefor transmission exists. That is, the RRC_INACTIVE terminal uses thefirst BSR even if the number of logical channel groups in which dataavailable for transmission exists is more than one. The RRC_INACTIVEterminal sets the identifier of a logical channel group with the highestpriority among logical channel groups in which data available fortransmission exists in the logical channel group identifier field 2H-01,and sets in the first buffer size field 2H-03 the first buffer sizeindex corresponding to the amount of data available for transmissionacross all the logical channels.

The RRC_INACTIVE terminal uses the logical channel group identifierpredefined in the specification instead of the logical channel groupidentifier configured in the RRC_CONNECTED state. In the RRC_INACTIVEstate, the terminal uses the preconfigured configuration instead of theterminal specific configuration because the base station does not knowthe terminal's buffer status reporting configuration.

The RRC_CONNECTED terminal determines the buffer size index to be set inbuffer size field of the BSR by considering only the data of the PDCPlayer and the data of the RLC layer. If RRC_INACTIVE terminal operatesin the same manner, remaining LPP segments stored in LPP layer is notconsidered. To overcome this problem, the RRC_INACTIVE terminaldetermines the buffer size index to be set in buffer size field byconsidering the amount of data of PDCP layer and data of RLC layer anddata of LPP layer (or upper layers of PDCP layer or upper layers of RRClayer). That is, a buffer size index corresponding to the sum of all thedata amounts is selected.

In step 3E-09, the base station transmits a locationInformation segmentto the LMF.

In step 3E-11, the terminal transmits the MAC PDU including the LPPsegment message and information indicating no more data fortransmission. The LPP segment message includes the last segment of theLPP ProvideLocatinoInformation message. Information indicating no moredata for transmission may be the first BSR in which buffer size index 0is set.

In step 3E-13, the base station transmits a locationInformation segmentto the LMF. After receiving the last segment, the LMF assembles thesegments to make a location information message and determines thelocation of the terminal by referring to the positioning measurementresult of the location information message.

In steps 3E-15, the terminal monitors whether the assistance datavalidity is met.

In step 3E-16, when it is determined that the assistance data of theconditional assistance data for which the assistance data validity issatisfied is determined to be valid, the terminal starts measuring thedownlink PRSs specified in the assistance data.

In step 3E-17, the terminal transmits the MAC PDU includingResumeRequest, LPP segment message and BSR (Buffer Status Report) to thebase station.

In step 3E-19, the base station transmits a locationInformation segmentto the LMF.

In step 3E-21, the terminal transmits the MAC PDU including the LPPsegment message and information indicating no more data fortransmission.

In step 3E-23, the base station transmits an LPP segment message to theLMF. After receiving the last segment, the LMF assembles the segments togenerate a location information message and determines the location ofthe terminal by referring to the positioning measurement result of thelocationInformation message.

If the terminal transitions to RRC_IDLE or RRC_CONNECTED or theassistance data validity is not met, the terminal stops measuring thedownlink PRS for location measurement and reporting the measurementresult.

FIG. 4 is a diagram illustrating an operation of a terminal.

In step 4A-01, the UE receives a first location protocol messageincluding first information for a location method in an inactive statefrom the location management function.

In step 4A-03, the UE receives radio resource control release includingconfiguration information for small data transmission through thesignaling radio bearer 2.

In step 4A-05, the UE enters an inactive state.

In step 4A-07, if the first information is included in the assistancedata providing message, the UE performs the positioning method in aninactive state.

In step 4A-09, the terminal transmits to the base station a MAC PDUincluding a first MAC subPDU for signaling radio bearer 0 resourcecontrol message and a second MAC subPDU for signaling radio bearer 2resource control message and a third MAC subPDU for buffer statusreport.

The signaling radio bearer 0 resource control message is a resumerequest and the SRB2 resource control message includes a segmentation ofthe location protocol message for the location measurement result.

The first MAC subPDU, the second MAC subPDU, and the third MAC subPDUare sequentially located in the MAC subPDU.

The first MAC subPDU does not contain the ciphered part, the second MACsubPDU contains ciphered part, and the third MAC subPDU does not containthe ciphered part. In other words, MAC subPDUs including ciphered partsare located between MAC subPDUs that do not contain ciphered parts.

The MAC sub header of the first MAC subPDU is composed of two reservedbits and one logical channel identifier field, and the MAC sub header ofthe second MAC subPDU includes one reserved bit, one format field, andone logical channel identifier field. It consists of a logical channelidentifier field and one length field, and the MAC subheader of thethird MAC subPDU consists of two reserved bits and one logical channelidentifier field.

The positioning method is a downlink arrival time difference based onpositioning reference signal measurement.

The first positioning protocol message may include help information fora positioning reference signal.

The first positioning protocol message may include report configuration.

FIG. 5A is a block diagram illustrating the internal structure of a UEto which the disclosure is applied.

Referring to the diagram, the UE includes a controller 5A-01, a storageunit 5A-02, a transceiver 5A-03, a main processor 5A-04 and I/O unit5A-05.

The controller 5A-01 controls the overall operations of the UE in termsof mobile communication. For example, the controller 5A-01receives/transmits signals through the transceiver 5A-03. In addition,the controller 5A-01 records and reads data in the storage unit 5A-02.To this end, the controller 5A-01 includes at least one processor. Forexample, the controller 5A-01 may include a communication processor CPthat performs control for communication and an application processor APthat controls the upper layer, such as an application program. Thecontroller controls storage unit and transceiver such that UE operationsillustrated in FIG. 2A and FIG. 2B and FIG. 3A are performed.

The storage unit 5A-02 stores data for operation of the UE, such as abasic program, an application program, and configuration information.The storage unit 5A-02 provides stored data at a request of thecontroller 5A-01.

The transceiver 5A-03 consists of a RF processor, a baseband processorand plurality of antennas. The RF processor performs functions fortransmitting/receiving signals through a wireless channel, such assignal band conversion, amplification, and the like. Specifically, theRF processor up-converts a baseband signal provided from the basebandprocessor into an RF band signal, transmits the same through an antenna,and down-converts an RF band signal received through the antenna into abaseband signal. The RF processor may include a transmission filter, areception filter, an amplifier, a mi10r, an oscillator, adigital-to-analog converter (DAC), an analog-to-digital converter (ADC),and the like. The RF processor may perform MIMO and may receive multiplelayers when performing the MIMO operation. The baseband processorperforms a function of conversion between a baseband signal and a bitstring according to the physical layer specification of the system. Forexample, during data transmission, the baseband processor encodes andmodulates a transmission bit string, thereby generating complex symbols.In addition, during data reception, the baseband processor demodulatesand decodes a baseband signal provided from the RF processor, therebyrestoring a reception bit string.

The main processor 5A-04 controls the overall operations other thanmobile operation. The main processor 5A-04 process user input receivedfrom I/O unit 5A-05, stores data in the storage unit 5A-02, controls thecontroller 5A-01 for required mobile communication operations andforward user data to I/O unit 5A-05.

I/O unit 5A-05 consists of equipment for inputting user data and foroutputting user data such as a microphone and a screen. I/O unit 5A-05performs inputting and outputting user data based on the mainprocessor's instruction.

FIG. 5B is a block diagram illustrating the configuration of a basestation according to the disclosure.

As illustrated in the diagram, the base station includes a controller5B-01, a storage unit 5B-02, a transceiver 5B-03 and a backhaulinterface unit 5B-04.

The controller 5B-01 controls the overall operations of the main basestation. For example, the controller 5B-01 receives/transmits signalsthrough the transceiver 5B-03, or through the backhaul interface unit5B-04. In addition, the controller 5B-01 records and reads data in thestorage unit 5B-02. To this end, the controller 5B-01 may include atleast one processor. The controller controls transceiver, storage unitand backhaul interface such that base station operation illustrated inFIG. 2A and FIG. 2B are performed.

The storage unit 5B-02 stores data for operation of the main basestation, such as a basic program, an application program, andconfiguration information. Particularly, the storage unit 5B-02 maystore information regarding a bearer allocated to an accessed UE, ameasurement result reported from the accessed UE, and the like. Inaddition, the storage unit 5B-02 may store information serving as acriterion to deter mine whether to provide the UE with multi-connectionor to discontinue the same. In addition, the storage unit 5B-02 providesstored data at a request of the controller 5B-01.

The transceiver 5B-03 consists of a RF processor, a baseband processorand plurality of antennas. The RF processor performs functions fortransmitting/receiving signals through a wireless channel, such assignal band conversion, amplification, and the like. Specifically, theRF processor up-converts a baseband signal provided from the basebandprocessor into an RF band signal, transmits the same through an antenna,and down-converts an RF band signal received through the antenna into abaseband signal. The RF processor may include a transmission filter, areception filter, an amplifier, a mi10r, an oscillator, a DAC, an ADC,and the like. The RF processor may perform a down link MIMO operation bytransmitting at least one layer. The baseband processor performs afunction of conversion between a baseband signal and a bit stringaccording to the physical layer specification of the first radio accesstechnology. For example, during data transmission, the basebandprocessor encodes and modulates a transmission bit string, therebygenerating complex symbols. In addition, during data reception, thebaseband processor demodulates and decodes a baseband signal providedfrom the RF processor, thereby restoring a reception bit string.

The backhaul interface unit 5B-04 provides an interface forcommunicating with other nodes inside the network. The backhaulinterface unit 5B-04 converts a bit string transmitted from the basestation to another node, for example, another base station or a corenetwork, into a physical signal, and converts a physical signal receivedfrom the other node into a bit string.

What is claimed is:
 1. A method by a terminal, the method comprising:receiving by the terminal from a base station a first type1 assistancedata, the first type1 assistance data includes a first type identifierand one or more Positioning Reference Signal (PRS) resource set;receiving by the terminal from the base station a type2 assistance data,the type2 assistance data includes a validity information and a secondtype1 assistance data; determining by the terminal based on the validityinformation and a New Radio (NR) cell global identifier of serving cellwhether the second type1 assistance data is valid; receiving by theterminal from the base station a RRCRelease, the RRCRelease includes aSuspendConfig, the SuspendConfig includes information indicating thatsmall data transmission is configured for Signaling Radio Bearer2(SRB2); and transmitting by the terminal in RRC_INACTIVE state aProvideLocationInformation, wherein at least a part of theProvideLocationInformation is transmitted in a first Medium AccessControl (MAC) Protocol Data Unit (PDU), the first MAC PDU includes aResumeRequest.
 2. A terminal in a wireless communication system, theterminal comprising: a transceiver configured to transmit and receive asignal, and a controller configured to control the transceiver to:receive from a base station a first type1 assistance data, the firsttype1 assistance data includes a first type identifier and one or morePositioning Reference Signal (PRS) resource set; receiving from the basestation a type2 assistance data, the type2 assistance data includes avalidity information and a second type1 assistance data; determine basedon the validity information and a New Radio (NR) cell global identifierof serving cell whether the second type1 assistance data is valid;receive from the base station a RRCRelease, the RRCRelease includes aSuspendConfig, the SuspendConfig includes information indicating thatsmall data transmission is configured for Signaling Radio Bearer2(SRB2); and transmit in RRC_INACTIVE state a ProvideLocationInformation,wherein at least a part of the ProvideLocationInformation is transmittedin a first Medium Access Control (MAC) Protocol Data Unit (PDU), thefirst MAC PDU includes a ResumeRequest.